Needle eye threading device



1966 YOSHIHIKO ASAHATA 3,291,084

NEEDLE EYE THREADING DEVICE Filed April 1, 1964 FIG.

FIG.

FIG. 3

I NVEN TOR.

BY M- United States Patent i 3,291,084 NEEDLE EYE THREADING DEVICEYoshihiko Asahata, 151 Z-chome Shimoshinjo-maelii, Higashiyodogawa-ku,OSaka shi, Japan Filed Apr. 1, 1964, Ser. No. 356,423 1 Claim. (Cl.112225) This invention relates to a new and improved device capable ofeasily passing thread through the eyes of needles such as sewing needlesand embroidering needles used in the production of sewn products andembroidered products.

Heretofore, such needle threading operation has, in almost all cases,been carried out by hand. Such practice is inefiicient and requiresexperience and skill, a high degree of skill being required particularlyin cases where a large number of needles are required to be operated atone time as, for example, in an embroidery lace machine.

It is an object of the present invention to overcome this deficiency byproviding a device of relative simple construction capable of easily andrapidly threading the eyes of needles.

It is another object of the invention to provide a device of the abovestated character which can be operated by a large number of operatorswho are not highly skilled.

It is a further object to provide a device of the above stated characterwhich is capable of rapidly threading a large number of needles.

It is a still further object to provide a device of the above statedcharacter which is adaptable to and contributive to automatization ofneedle threading work.

With the foregoing objects and other specific objects in view, theinvention resides in the novel arrangement and combination of parts andin the details of construction hereinafter described and claimed,reference being had to the accompanying drawings in which like parts aredesignated by like reference characters, and in which:

FIGURE 1 is an elevational view, with a part cut away, showing theembodiment of the needle threader according to the invention;

FIGURE 2 is a sectional view of the section taken along the planeindicated by line II-II in FIGURE 1;

FIGURE 3 is a sectional view of the section taken along the planeindicated by line IIIIII in FIGURE 1; and

FIGURE 4 is a sectional view of the section taken along the planeindicated by line IVIV in FIGURE 1.

Referring to the drawings, the support structure of the embodiment ofthe invention shown consists essentially of a base plate 1, a coverplate 2 disposed parallelly and secured by a screw 4 to the base plate 1with a suitable gap therebetween, and a bar 3 which is directed in adirection parallel to a support member (not shown), and to which bar 3the root part of the cover plate 2 is perpendicularly fixed. The bar 3is so supported that it is capable of rotating about its axis and,moreover, of moving to the left and right as viewed in FIGURES 1 and 2.The rotational and left and right movements of this bar 3 may beeffected automatically by mechanical power means (not shown) ormanually.

In the gap between the base plate 1 and the cover plate 2, there isprovided a guide lever 7 having a hook part 6 at its free end andpivoted at its other end on a pin supported on the base plate 1 andcover plate 2. This guide lever 7 is made to have a thickness such thatit can freely pass through the eye 14 of a sewing needle (or embroideryneedle) a placed in the needle threading device.

The outer end (that is, the right-hand end as viewed in FIGURES l and 2)of the base plate 1 is provided with a bent back part 8 curved towardthe side of the cover plate 2 and then back toward the fixed end of thecover plate 2. A gap is provided between the extreme end of the easiestPatented Dec. 13, 1966 cover plate 2 and the extreme end of this bentback part 8 so as to permit the passing therethrough of a needle withsuflicient clearance. Stepped cutouts 2 and 1 are provided respectivelyat the outer end of the base plate 2 and the part of the base plate 1confronting said outer end, said stepped cutouts 2 and 1 being inmutually facing and symmetrical disposition so as to form a groove foraccommodating a needle to be threaded as will be described hereinafter.At approximately central parts of the bent back part 8 and the end partof the base plate 1 facing the bent back part 8, there are formedrespective threading slots 9, 9 of converging shape extending upwardlyat an inclined angle from the outer edge of the said parts as shown mostclearly in FIGURE 1. The inner ends of these threading slots 9, 9communicate with respective thread receiving holes 10, 10 formed in thebase plate 1 and bent back plate 8 at positions within the radius ofrotation of the afore-mentioned hook part 6 of the guide lever 7.

A stop 11 is fixed to the base plate 1 so as to limit the rotationalrange of the guide lever 7 in the clockwise direction as viewed inFIGURE 1. A spring 12 is provided to impart a moment to the guide lever7 always urging it to rotate in the clockwise direction as viewed inFIGURE 1, and this rotational tendency can be locked by a latch member13. .This latch member 13 is supported on the base plate 1 in a mannerpermitting it to be projected out and retracted at a relative positionsuch that, at the time of retraction of the needle a, as will bedescribed more fully hereinafter, when the guide lever 7 caused torotate by actuation due to the eye 14 disengages from the eye 14 of thisretracting needle a, the latch member 13 locks the guide lever 7, whichis normally in this locked state when not in use. Reference characters14,, and 14 designate depressions generally formed on the left and rightsides of the eye 14 of the needle a.

The needle threading device of the invention of the above describedconstruction operates in the following manner. When a thread passedthrough a needle a breaks because of some cause, this thread break canbe readily detected in both the case of a sewing machine and the case ofan embroidery lace machine (in which latter case an automatic monitoringand indicating means such as buzzer or a blinker lamp is usuallyprovided).

When, in such a machine provided with the needle threading device ofthis invention mounted in a suitable position therein, a thread break isdetected, the latch member 13 is retracted (downwardly as viewed inFIGURE 2) by a manually operated mechanism or by any suitable means suchas an electromagnetic device (not shown) activated by an automaticmonitoring and indicating system. Consequently, the guide lever whichhas been locked by the latch member 13 is released and is caused by thespring 12 to rotate in the clockwise direction (as viewed in FIGURE 1)until it is stopped by the stop 11.

When the needle threader in the above described state is rotated by therotation of the bar 3 to the side of the needle a, the extreme end ofthe bent back part 8 of the base plate 1 and the extreme end of thecover plate 2 pass by opposite sides of the needle a with sufiicientclearance, whereby, in relative effect, the needle a enters through thegap between the two said extreme ends. Then the needle threader isshifted together with the bar 3 to the right as viewed in FIGURES 1 and2, whereupon the needle a is encompassed on three sides by theaforementioned groove formed by the stepped cutouts 1 and 2,, 'formed inthe base plate 1 and the cover plate 2. Accordingly, if the needle a isadvanced beforehand to the appropriate position, the hook part 6 of theguide lever '7 will fit into the eye 14 of the needle a. This state ofthe operation is shown in FIGURE 1.

On one hand, a thread end b drawn out from a bobbin (not shown) isintroduced at a suitable time after the above described operational stepor prior thereto through the threading slots 9, 9 on the base plate 1into the thread receiving holes 10, 10, a thread end of suitable surpluslength being left.

Then when, with the needle threader, needle, and thread in the abovedescribed state, the needle a is retracted, the guide lever 7 isactuated accordingly by the eye 14 of the needle a to rotate in thecounter-clockwise direction (as viewed in FIGURE 1) against the elasticforce of the spring 12. As the retraction of the needle a proceeds andreaches approximately the midpoint of its stroke, the hook part 6 of theguide lever 7 passes through the eye 14 to the opposite side. Then, asthe retraction of the needle a proceeds further, the resulting rotationof the guide lever 7 causes the hook part 6 to hook the thread b at itsspan between the thread receiving holes 10, 10. Still further retractionof the needle a causes further rotation of the guide lever 7 whereby thehook part 6, still with the thread b hooked therein, is caused to beginwithdrawal from the eye 14, and the guide lever 7 overrides the latchmember 13 and is locked thereby.

The working end of the latch member 13 is preferably provided with aninclined surface as indicated in FIG- URE 2 so as to facilitate thepassing of the guide lever 7 thereover. At this point in the operationwhen the guide lever 7 is locked by the latch member 13, the hook part 6of the lever 7 is in the state of being almost completely withdrawn fromthe eye 14 as indicated by the two-dot chain line in FIGURE 1, and thethread end b from the bobbin is in a state of being passed almostcompletely through the eye 14.

Then, after the needle threader has been shifted to the left as viewedin FIGURES 1 and 2, the needle a is caused to advance. Consequently, andsince the guide lever 7 is locked by the latch member 13, the thread b,which, having been hooked by the hook part 6 at the tip of the guidelever 7, is stretched between the hook part 6 and the thread receivingholes 10, 10, is further stretched as the needle a advances, whereby thethread part on the bobbin side from the hook part 6 is pressed by theeye 14 and is drawn out from the bobbin. At this time, the thread partfrom the hook part 6 to the extreme end of the thread becomesprogressively shorter as the needle a advances and would finally slipoff the hook part 6 if it were short. However, if this thread end isprovided with a sufiicient surplus length as mentioned hereinbefore, itwill not pass out, unthreaded, from the eye 14 toward the bobbin side.

On the other hand, the thread part extending from the hook part 6 by wayof the thread receiving hole to the bobbin slips out of the threadingslot 9 during the latter part of the advance of the needle a because ofthe inclination of the threading slot 9.

The entrance parts of this threading slot 9 and the end part of theneedle threader assembly contiguous thereto are preferably formed tohave rounded, fair contours as indicated in FIGURE 1 so as to facilitatethe smooth separation of the thread from the threading slot 9.

The needle threading operation is thus completed, and the sewing (orembroidering) operation can be resumed. If necessary, the needlethreader assembly may be adapted to rotate together with the bar 3 to beamply separated from the neede a for resumption of sewing (orembroidering).

From the foregoing disclosure, it will be seen that the presentinvention provides a needle threading device by the use of which threadcan be passed through the eyes of needles by any number of operatorswithout high skill, whereby Work efficiency can be greatly increased.Moreover, the needle threading device of the invention is adaptable toand contributive to automatization of needle threading steps and isparticularly suitable and useful for application to machines such asembroidery lace machines wherein a large number of needles are operatedat the same time.

It should be understood, of course, that the foregoing disclosurerelates to only a preferred embodiment of the invention and that it isintended to cover all changes and modifications of the example of theinvention herein chosen for the purposes of the disclosure, which do notconstitute departures from the spirit and scope of the invention as setforth in the appended claim.

What I claim is:

A device for passing thread through the eye of a needle, comprising incombination,

(a) a base plate having a bent back part provided with threading slotsfor holding thread and a cover plate disposed parallel and secured tosaid base plate with a suitable gap therebetween, confronting ends ofsaid bent back part and cover plate being spaced apart so as to insert aneedle to be threaded therethrough, said base and cover plates defininga guide groove to hold said needle therein towards the outer end of saidcover plate and part of the base plate confronting said cover plateouter end;

(b) a guide lever including a hook portion pivotally supported in saidgap between said plates, said hook portion being positioned to freelypass through the eye of a needle located in said guide groove, saidguide lever being adapted to be rotated by said needle eye when theneedle undergoes longitudinal movement, the length of the lever beingselected so as to be rotated by said needle movement and passed firstthrough the needle eye from one side of the needle to the other sidethereof, and, as its rotation progresses, passed between said threadingslots on the other side so as to hook onto thread therein, and backthrough said eye to said one side by further rotation of said guidelever thereby drawing and passing said thread through the needle eye;

(c) a latch member, supported on said base plate so as to project outand retract to lock said guide lever when the device is not used; and,

(d) a stop fixed to the base plate to limit the rotational range of theguide lever.

References Cited by the Examiner UNITED STATES PATENTS 2,490,882 12/1949Pinkham et al. 223-99 2,518,287 8/1950 Costello 22399 2,543,587 2/1951Nas 223-99 2,552,731 5/1951 Pinkham et al. 112225 JORDAN FRANKLIN,Primary Examiner.

RICHARD J. SCANLAN, .TR., Examiner. I

